Atoms in 3D

The secret behind three-dimensional scenes in a movie is simple: the special glasses you wear separate blue and red images, creating two views that, when combined, produce an optical illusion. Now a scientist from the Nara Institute of Science and Technology in Japan has proposed a similar tactic for generating 3-D images of atoms. Hiroshi Daimon describes the idea in this week's Physical Review Letters.

One method physicists use to produce images of atomsphotoelectron diffractionrelies on high-energy photons that shake free some of electrons in a sample. These electrons then produce a diffraction pattern, from which some believe the sample's structure can be read. Daimon worked out a variation on this theme, bombarding crystals with circularly polarized light. The photons in this light have spin and angular momentum, which they transfer to the electrons they knock loose. As a result, the diffraction pattern is slightly rotated, either clockwise or counterclockwise depending on the original light.

Using both left and right circularly polarized light, Daimon created two different points of view of the same tungsten crystal (see image). These different vantages, he says, can be merged into a stereoscopic 3-D image. Further experimentation is needed to confirm that the technique really can work, but if it does, it might also be used to produce real-time 3-D video of atoms and molecules.